Non-metallic, bio-compatible hemostatic clips with interlocking latch means

ABSTRACT

Sterile, non-metallic, bio-compatible hemostatic clips of absorbable and non-absorbable materials comprising two leg members joined with a resilient hinge. The distal ends of said leg members include latch means to lock the clip in a closed position. Each leg member has a vessel clamping inner face and the latch means includes means for preventing relative lateral movement between the vessel clamping inner faces when the clip is in a closed position.

The present invention relates to hemostatic clips and clip appliers,and, more particularly, to hemostatic clips fabricated from absorbableor nonabsorbable polymeric materials and to instruments for applyingsuch clips to blood vessels and the like.

BACKGROUND OF THE INVENTION

In many surgical procedures, it is often necessary to ligate a pluralityof vessels within the surgical site. The vessels may then be severeddownstream of the ligated portion. In some instances, the vessel may beligated at two areas, spaced from one another, and the portion of thevessel between the ligation removed. The primary reason for ligating thevessels is to maintain the surgical site free of an excess of blood andto reduce blood loss in the patient. Also in certain surgical procedureswherein tumors or parts of organs and the like are to be removed, thetumor or organ may have to be separated from certain vessels which,before separating, will have to be ligated.

Once a blood vessel is completely shut off, hemostasis; that is, thenatural closing of the ligated end of the vessel so as to stop bloodflow, will occur in about 3 to 5 days. The body, in the meantime, willcontinue to allow blood to flow around the ligated area throughappropriate capillaries and secondary vessels. The natural physiologicalfunctions of the body eventually enlarge these by-pass vessels untiladequate blood flow is attained. Hence, when ligating the vessel, thereshould be a positive stopping of the blood flow in the main vessel;i.e., no leakage, which might cause blood loss in the patient and maydisrupt the natural hemostasis and concurrent manufacture of new pathsof blood flow in the patient.

In the past, this closing of the vessel was usually accomplished usingligatures; i.e., threads or filaments which the surgeon tied around thevessel desired to be closed. This is a very time-consuming process andone in which positive closure of the vessel was not always accomplished.

In relatively recent years hemostatic clips have replaced ligatures inmany surgical procedures to close blood vessels and other small fluidducts. In the past, hemostatic clips have been narrow U-shaped orV-shaped strips formed of tantalum or stainless steel which are capableof being deformed and possess sufficient strength to retain thedeformation when clamped about a blood vessel. The clips are generallyapplied using a forceps-type device having jaws channeled or otherwiseadapted to hold the open clip. Representative hemostatic clips andappliers of the prior art are best illustrated in U.S. Pat. Nos.3,867,944; 3,631,707; 3,439,523; 3,439,522; 3,363,628; 3,312,216; and3,270,745.

Although the metal hemostatic clips are relatively easy to apply andaccomplish a positive closing of the vessel, the metal devices areexpensive to manufacture and perhaps, more importantly, disrupt postoperative X-ray procedures and subsequent diagnostic imaging procedures.Hence, it is desired that hemostatic clips be made from materials whichwill not disrupt the post-operative or other subsequent diagnosticprocedures, such as X-ray imaging, computerized axial tomographyimaging, and the like.

It is critical that hemostatic clips used in surgery be sterilizable bythe well known sterilizing techniques; such as, ethylene oxidetreatment, cobalt irradiation, and the like without loss infunctionality of the clip.

It has been suggested in the prior art, as in U.S. Pat. No. 3,439,523for example, that hemostatic clips might be formed of inexpensiveplastics or materials which are slowly absorbable in the body.Unfortunately, conventional U- and V-shaped hemostatic clips do notpossess the required strength or deformability when constructed of knownplastic materials to be successfully clamped about a blood vessel. Thus,although the need and desirability of providing inexpensivenon-metallic, bio-compatible hemostatic clips of both absorbable andnonabsorbable materials has been recognized for over ten years, therehas been no practical way to satisfy this need.

To accomplish the positive closing of the vessel with non-metallic,bio-compatible hemostatic clips, the vessel clamping surfaces of theclips should have substantially no gap between the surfaces when theclip is closed. Also, the surfaces should be sufficiently smooth andhave large enough areas so as not to sever or even partially sever theclosed vessel. The non-metallic, bio-compatible hemostatic clip, onceplaced in a clamping position on a vessel, must maintain that positionfor the period of time required for hemostasis to take place. The clipmust maintain its strength in vivo to withstand the pressure trying toforce the vessel back open for a sufficient period of time to allow forthe natural permanent shutting of the vessel.

The configuration of a hemostatic clip is also important. Because theclip is often used in and around the important organs of the body andthe clip is left in the body after the subject surgical procedure iscompleted, it is important that the clip be configured to keep traumawithin the area; i.e., irritation from a foreign object, to a minimum.Smoothness and size of the clip as well as a lack of projections and aminimum of sharp angles all contribute to reducing the trauma which mayoccur when placing a foreign object such as a hemostatic clip, within ahuman body.

The clip configuration is also important to insure the proper placementof a clip. When hemostatic clips are used in a surgical procedure, thegeneral practice is for the nurse to pick up the clip in the jaws of aforceps type applying instrument. The nurse passes the instrument withthe clip in place to the surgeon. The surgeon places the jaws of theinstrument into the surgical site and around the vessel to be ligated.In many instances, the surgeon will be placing the jaws of theinstrument into areas where the surgeon has very limited vision. Thesurgeon then closes the clip over the vessel to be ligated. All of thehandling and manipulation of the instrument must be accomplished withoutdropping the clip and while maintaining the sterility of the clip.

The size of the clip is also important as the smaller the clip, the lessforeign material there is being implanted in the patient. Also, thesmaller size allows for more clips to be used in a surgical procedureand in certain instances may simplify the procedure or at least reducepossible side effects resulting from the insertion of foreign objectswithin the human body.

U.S. Pat. No. 3,926,195 describes a plastic clip designed for thetemporary or permanent closing of the oviduct and vas deferens inhumans. These clips preferably have a clamping surface of from 6 to 10mm in length and 3 to 6 mm in width. The size of such clips areaccordingly considerably larger than is desirable for hemostatic clips.Additionally, clips of U.S. Pat. No. 3,926,195 require the use ofseveral complex tools to apply the clips which are acceptable for thepurposes descirbed in the reference but would be unacceptable in asurgical procedure requiring the rapid placement of a large number ofhemostatic clips to stem the flow of blood from severed vesselsespecially when these clips have to be placed in relatively inaccessibleareas of the body.

In copending commonly assigned patent applications, Ser. Nos. 49,376,49,375 and 49,379, all filed June 18, 1979, there are disclosed a numberof different types of non-metallic, bio-compatible surgical clips ofvarious configurations. Also, in copending commonly assigned patentapplication Ser. No. 123,878 filed Feb. 25, 1980, which is incorporatedherein by reference, there is disclosed a non-metallic, bio-compatibleclip configuration wherein both ends of the clip are mechanically lockedin place in the closed position.

Though these clips are suitable for many surgical procedures, they allsuffer from the problem that the legs themselves may laterally shiftwith respect to each other so that their vessel clamping surfaces arenot disposed fully flush with respect to each other which may allow thelocking end of the clip to open. This problem increases the smaller thewidth of the clip and the longer the clip legs.

While the importance of the clip to the surgical procedure has beendiscussed, it should be pointed out that the configuration of the clipis also important to the manufacture of the clip. The configurationshould be such as to take advantage of simple and economic means ofmanufacture of the clip such as injection molding. The configurationshould be such as to reduce the production of seconds or malformed clipsduring manufacture. Also, the configuration of the clip should be suchas to allow for very simple design of the applier while maintaining therequired assurance of holding and setting the clip during the surgicalprocedure.

It is accordingly an object of the present invention to provide sterile,non-metallic, bio-compatible hemostatic clips effective for clamping offsmall blood vessels and other fluid ducts in the body. It is a furtherobject of this invention to provide sterile non-metallic, bio-compatiblehemostatic clips of both absorbable and nonabsorbable materials. It isyet a further object of this invention to provide sterile, non-metallic,bio-compatible ligating clips which are quickly and easily applied tosevered blood vessels and other fluid ducts with a single forceps-typeinstrument such as those used in applying metallic clips. It is yet afurther object of this invention to provide non-metallic, bio-compatibleligating clips which are securely locked in place to prevent theirvessel clamping surfaces from moving laterally with respect to eachother when the clip is in the closed position.

SUMMARY OF THE PRESENT INVENTION

The hemostatic clips of the present invention comprise two leg membersjoined at the proximal ends thereof along a line forming a resilienthinge, with the first leg member, having at its distal end, a latchmeans adapted to engage a complementing latch means at the distal end ofthe second leg member. Each leg member has a vessel clamping inner facein opposition to a vessel clamping inner face of the other leg member.The latching means includes means to prevent relative lateral movementbetween the clamping inner faces when the clip is in the closedposition. Each leg member also includes applier gripping means disposedon its outer surface for use in holding and closing the clip during itsapplication.

The applier for the clips of the present invention is a forceps-typeinstrument wherein each jaw is channeled to receive the width and lengthof the clip and accept the applier gripping means on the outer surfaceof the legs of the clip.

In a preferred embodiment of the clip of the present invention, theproximal ends of the leg members containing the hinge section areconstructed so as to mechanically lock at this end when the clip isclosed.

The clips may be formed of various polymers by injection molding orother suitable technique, and may be composed of a nonabsorbablematerial such as polypropylene or an absorbable material such as ahomopolymer or copolymer of lactide and glycolide and p-dioxanone. Theclips are formed in a normally open position and constructed with asmall amount of material to minimize tissue reaction. The clips arereadily applied with a forceps-type applier using conventional surgicaltechniques.

DESCRIPTION OF DRAWINGS

FIG. 1 is a greatly enlarged view in perspective of one embodiment of asurgical clip according to the present invention.

FIG. 2 is a greatly enlarged view in perspective of another embodimentof a surgical clip according to the present invention.

FIG. 3 illustrates the clip of FIG. 2 clamped about a blood vessel.

FIG. 4 illustrates a forceps-type applier useful with the clips of thepresent invention.

FIG. 5 illustrates the open clip of FIG. 1 retained in the jaws of aforceps-type clip applier.

FIG. 6 illustrates the clip of FIG. 1 closed and locked over a bloodvessel in the jaws of the applier.

FIG. 7 is an enlarged perspective view of another embodiment of aninterlocking clip of the present invention.

FIG. 8 is an enlarged perspective view of yet another embodiment of aninterlocking clip of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIG. 1, there is illustrated a hemostatic clip 10constructed of two leg members 11 and 12 connected at the proximal endsthereof by a hinged section 13. One leg member 11 has disposed at itsdistal end a protrusion 14 while the opposite leg member 12 hasdisposed, at its distal end, a recess 15 for accepting the protrusion.The vessel clamping inner face 16 of the second leg member 12 isdisposed in opposed relationship to the vessel clamping inner face 19 ofthe opposite or first leg member 11. In this embodiment, the hinged areais constructed so that in closing, the surface 20 of the second legmember 12 pivots at the hinge and is locked under the surface 21. Thisstructure provides for a mechanical locking of leg 12 when the clip isin a closed position. This feature becomes important with biologicallyabsorbable materials in that this mechanical lock maintains the hingeend closed for an extended period during the absorption process.

The leg member 12 of the clip includes a boss 23 extending across thewidth of the leg member near at the distal end thereof. The leg member11 of the clip also includes a boss 22 extending across the width of theleg member near the distal end thereof. These bosses are constructed soas to engage complimentary recesses in forceps to retain and control theclip while it is being applied.

The bosses are generally cylindrical in construction so as to distributethe forces, and rotate journal like during the closing of the clip. Thebosses are spaced from the hinge area and positioned close to the latcharea to provide adequate leverage in the closing of the clip about avessel.

It is preferred that the proximal ends of leg members 11 and 12 beslightly tapered being smaller at hinge section 13. This featureprovides flexure of the leg member over tissue. This feature alsoprovides a relief area or gap between this area and the clip applyinginstrument so that the clip closing forces are applied preferentially tothe portion of the clip carrying the bosses.

Referring to FIG. 2, there is shown another embodiment of a hemostaticclip 30 in accordance with the present invention. In this embodiment,the leg members 31 and 32 are connected at their proximal end by hingedsection 33. One leg member 31 includes a curved section 34 at its distalend.

At the beginning of the curved section 34, there is a recessed area 35and the curved section terminates in protrusion 36. The opposite legmember 32 terminates in a recessed area 37 configured to accept theprotrusion 36. This leg member 32 also carries a protrusion 38 adaptedto fit into the recessed area 35 of the opposite leg member. Each legmember carries on its outer surface a boss 39 for use in retaining andapplying the clip to close off a blood vessel. When the vessel clampinginner face 41 of leg member 31 is urged toward the vessel clamping innerface 42 of leg member 32 and when the clamping faces are adjacent eachother protrusion 36 will fit into the recess 37 and protrusion 38 willfit into recess 35 and will prevent relative lateral movement betweenthe clamping faces.

FIG. 3 depicts the clip shown in FIG. 2 in position about a blood vesselwith the vessel clamping inner faces 41 and 42 of the clip 30 closingoff the vessel 43.

FIG. 4 illustrates a forceps-type hemostatic clip applier 50 comprisingtwo handle members 51 and 52 crossing at hinge point 53 and maintainedin a normally open position by spring 58. Handle 51 extends beyond hinge53 forming jaw member 54 while the extension of handle 52 forms jawmember 55.

FIG. 5 illustrates the detail of the construction of jaws 54 and 55 andthe interaction of the jaws with the clip of FIG. 1. Jaws 54 and 55 areof identical design and are provided respectively with channels 56 and57 extending rearwardly from the tips of the jaws. Each channel isprovided with a cylindrical recess 58 and 59 respectively across thewidth of the channel and near the distal end thereof. Recesses 58 and 59are in alignment when the jaws of the applier are closed and are sizedto receive the cylindrical bosses 22 and 23 of the clip. Channels 56 and57 forward of recesses 58 and 59 are deeper than to the rear of therecesses as illustrated in FIG. 5. When the open clip is held in theapplier, the bosses on the clip are received by the recesses in eachjaw. Due to the angle of the clip in the applier, the distal ends oflegs 11 and 12 extend into the deeper forward channel section of eachjaw.

The clip is molded with a larger internal angle than is shown in FIG. 5when the clip is in the applier. This feature uses the resilient hingeas a flexible spring to seat the bosses into the recesses in the applierjaws. As the hinge flexes, a spring action follows such that if theapplier is closed and opened a small amount, the clip will not fall outof the applier. This overcomes a substantial problem with the metal clipof the prior art which have a considerable tendency to fall out of thejaws of the applier if there is slight flexing of the applier duringhandling.

Clip 10 is initially loaded in applier 50 in the open position asillustrated in FIG. 5. After moving the jaws of the applier and the clipinto position over the vessel to be ligated, the jaws of the applier areclosed and the clip is locked in position over the vessel 69 asillustrated in FIG. 6. As the clip is closed, the cylindrical bosses oflegs 11 and 12 are rotably engaged by the cylindrical recesses of jaws57 and 56 and maintained in position in the by the hinge spring forceapplier until the protrusion 14 of leg member 11 is positioned withinand held by the recess 15 in leg member 12. After the clip has beensecurely latched over the vessel to be ligated, the jaws of the applierare opened to release the clip and vessel and a new clip is loaded inthe applier. Since the jaws of the applier are identical, it is notnecessary to orient the applier to the clip when loading the applier.

It should be pointed out that the cylindrical bosses on the clip and thecomplementary cylindrical recesses in the applying instrument areimportant to allow for positive gripping and closing of the clip. As maybe seen in FIGS. 5 and 6 the leg members of the clip move through anangle of about 75° when the clip is closed while the jaws of theinstrument only move through an angle of about 5° to 10°. Hence, theapplying gripping means on the clip must be free to rotate in the jawsof the applying instrument as the clip is being closed.

Referring to FIG. 7, there is illustrated a hemostatic clip 60constructed of two leg members 61 and 62 connected at the proximal endsthereof by a hinged section 63. The one leg member 61 terminates at itsdistal end in a recessed area 64 having a flexible flange 65 disposedabout the periphery of the area. The flange may partially close therecessed area or it may entirely close the recessed area and be cut toprovide for deflection. The second leg member 62 has disposed about itsinner surface at the distal end of the member a protrusion 66. Theprotrusion is conical in shape and is sized to snugly fit into therecessed area of the other leg member 61. A substantial portion of theouter surface 67 of the leg member 62 defines a curve of substantiallyconstant radius extending from its outer end. The effect of thiscurvature is to permit the clip to slide forward and rotate duringclosure. The curvature also reduces the thickness of the leg at thedistal end thereof. The clip as described in FIG. 7 is more fullydescribed as to the shape and curvature of its outer surfaces and themanner in which it is used and applied with specific forceps incopending commonly assigned patent application Ser. No. 49,376 filedJune 18, 1979.

As may be seen from both FIG. 1 and FIG. 7, when the clip is in theclosed position and the protrusion gripped by the recess, theconfiguration of the protrusion and the recess prevents lateral movementbetween the vessel clamping inner faces.

FIG. 8 shows still another embodiment of a hemostatic clip in accordancewith the present invention. In this embodiment the clip 70 comprises apair of leg members 71 and 72 connected at their proximal ends by aresilient hinge section 73. The distal end of leg member 71 terminatesin a vertically protruding hook section 74 and the distal end of legmember 72 terminates in a horizontally extending hook section 75. Thehook sections have complimentary configurations which interlock witheach other when the clip is closed and present lateral movement betweenthe vessel clamping inner faces 76 and 77. The outer surface of each legmember carries a plurality of ridges 78 as the gripper applying means.These ridges cooperate with a complementary plurality of groovesdisposed in the jaws of the forceps type applying instrument.

Many variations in the clip design other than the embodiments disclosedherein will be apparent to those skilled in the art and are contemplatedwithin the scope of the present invention.

The clips of the present invention may be constructed in various sizesaccording to their intended function. Hemostatic clips are typicallyless than 6 mm in length, about 1.5 mm in width, and have a vesselclamping surface about 3 mm in length. The dimensions of the clip may bereduced by about 50 percent for certain applications in microsurgery.Larger clips for special hemostatic applications and other functionssuch as closure of oviducts or vas deferens may have dimensions of aboutdouble those of a typical hemostatic clip. The various sizes of clipsare preferably matched with individual appliers having jaws tailored tothe size of the clip for best performance.

The clips of the present invention are most conveniently molded ofbiologically acceptable non-metallic materials which may be absorbableor nonabsorbable. Preferred absorbable polymers include homopolymers andcopolymers of glycolide and lactide, and p-dioxanone. Preferrednonabsorbable polymers include nylon and polypropylene. All thesematerials have been demonstrated to be biologically acceptable when usedas sutures or other implantable medical devices. The clips may also becast or machined from solid polymeric materials.

Having now described the invention in considerable detail, it should bereadily apparent to those skilled in the art that various modificationsand alterations may be made to the invention without departing from thespirit and scope thereof.

We claim:
 1. A sterile hemostatic clip for application to a blood vesseland the like by utilizing a clip applying instrument, said clipcomprising first and second leg members, each member having first andsecond sides joined by an outer surface and an elongated vessel clampinginner face in opposition to a vessel clamping inner face of the otherleg member, said leg members being connected at their proximal ends by aresilient hinge means, said first leg member terminating at its distalend in a return bend hook portion, said second leg member terminating atits distal end in a complementary latch means for engagement by saidhook portion of said first leg member, the hook portion of the distalend of said first leg member including a protrusion which is engagablein a recess in the distal end of said second leg member when said clipis in a closed position and said second leg member including aprotrusion adjacent the distal end thereof which is engagable in arecess adjacent the distal end of said first leg member; said cliphaving each of said protrusions in each of said recesses contiguous withthe same side of said first and second sides so that when said clip isin the closed position, with engagement between respective protrusionsand recesses, lateral movement between said vessel clamping inner faceis prevented.
 2. The hemostatic clip of claim 1 wherein said first andsecond leg members include applier gripping means disposed on the outersurfaces of the leg members adjacent the distal ends of said legmembers.
 3. The hemostatic clip of claim 2 wherein the applier grippingmeans comprises a cylindrical boss disposed on the outer surface of eachleg member and extending transversely across the width of said legmember.
 4. The hemostatic clip of claim 1 wherein said first and secondleg members include gripping means disposed on the outer surfaces of theleg members.
 5. The hemostatic clip of claim 1 wherein the return bendhook portion of the first leg member extends towards said resilienthinge means.